/* * Copyright © 2017 Intel Corporation * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS * IN THE SOFTWARE. */ #include "nir.h" #include "nir_builder.h" /** * \file nir_opt_intrinsics.c */ /* Converts a uint32_t or uint64_t value to uint64_t or uvec4 */ static nir_ssa_def * uint_to_ballot_type(nir_builder *b, nir_ssa_def *value, unsigned num_components, unsigned bit_size) { assert(value->num_components == 1); assert(value->bit_size == 32 || value->bit_size == 64); nir_ssa_def *zero = nir_imm_int(b, 0); if (num_components > 1) { /* SPIR-V uses a uvec4 for ballot values */ assert(num_components == 4); assert(bit_size == 32); if (value->bit_size == 32) { return nir_vec4(b, value, zero, zero, zero); } else { assert(value->bit_size == 64); return nir_vec4(b, nir_unpack_64_2x32_split_x(b, value), nir_unpack_64_2x32_split_y(b, value), zero, zero); } } else { /* GLSL uses a uint64_t for ballot values */ assert(num_components == 1); assert(bit_size == 64); if (value->bit_size == 32) { return nir_pack_64_2x32_split(b, value, zero); } else { assert(value->bit_size == 64); return value; } } } static nir_ssa_def * lower_read_invocation_to_scalar(nir_builder *b, nir_intrinsic_instr *intrin) { /* This is safe to call on scalar things but it would be silly */ assert(intrin->dest.ssa.num_components > 1); nir_ssa_def *value = nir_ssa_for_src(b, intrin->src[0], intrin->num_components); nir_ssa_def *reads[4]; for (unsigned i = 0; i < intrin->num_components; i++) { nir_intrinsic_instr *chan_intrin = nir_intrinsic_instr_create(b->shader, intrin->intrinsic); nir_ssa_dest_init(&chan_intrin->instr, &chan_intrin->dest, 1, intrin->dest.ssa.bit_size, NULL); chan_intrin->num_components = 1; /* value */ chan_intrin->src[0] = nir_src_for_ssa(nir_channel(b, value, i)); /* invocation */ if (intrin->intrinsic == nir_intrinsic_read_invocation) nir_src_copy(&chan_intrin->src[1], &intrin->src[1], chan_intrin); nir_builder_instr_insert(b, &chan_intrin->instr); reads[i] = &chan_intrin->dest.ssa; } return nir_vec(b, reads, intrin->num_components); } static nir_ssa_def * lower_subgroups_intrin(nir_builder *b, nir_intrinsic_instr *intrin, const nir_lower_subgroups_options *options) { switch (intrin->intrinsic) { case nir_intrinsic_vote_any: case nir_intrinsic_vote_all: if (options->lower_vote_trivial) return nir_ssa_for_src(b, intrin->src[0], 1); break; case nir_intrinsic_vote_eq: if (options->lower_vote_trivial) return nir_imm_int(b, NIR_TRUE); break; case nir_intrinsic_load_subgroup_size: if (options->subgroup_size) return nir_imm_int(b, options->subgroup_size); break; case nir_intrinsic_read_invocation: case nir_intrinsic_read_first_invocation: if (options->lower_to_scalar && intrin->num_components > 1) return lower_read_invocation_to_scalar(b, intrin); break; case nir_intrinsic_load_subgroup_eq_mask: case nir_intrinsic_load_subgroup_ge_mask: case nir_intrinsic_load_subgroup_gt_mask: case nir_intrinsic_load_subgroup_le_mask: case nir_intrinsic_load_subgroup_lt_mask: { if (!options->lower_subgroup_masks) return NULL; /* If either the result or the requested bit size is 64-bits then we * know that we have 64-bit types and using them will probably be more * efficient than messing around with 32-bit shifts and packing. */ const unsigned bit_size = MAX2(options->ballot_bit_size, intrin->dest.ssa.bit_size); assert(options->subgroup_size <= 64); uint64_t group_mask = ~0ull >> (64 - options->subgroup_size); nir_ssa_def *count = nir_load_subgroup_invocation(b); nir_ssa_def *val; switch (intrin->intrinsic) { case nir_intrinsic_load_subgroup_eq_mask: val = nir_ishl(b, nir_imm_intN_t(b, 1ull, bit_size), count); break; case nir_intrinsic_load_subgroup_ge_mask: val = nir_iand(b, nir_ishl(b, nir_imm_intN_t(b, ~0ull, bit_size), count), nir_imm_intN_t(b, group_mask, bit_size)); break; case nir_intrinsic_load_subgroup_gt_mask: val = nir_iand(b, nir_ishl(b, nir_imm_intN_t(b, ~1ull, bit_size), count), nir_imm_intN_t(b, group_mask, bit_size)); break; case nir_intrinsic_load_subgroup_le_mask: val = nir_inot(b, nir_ishl(b, nir_imm_intN_t(b, ~1ull, bit_size), count)); break; case nir_intrinsic_load_subgroup_lt_mask: val = nir_inot(b, nir_ishl(b, nir_imm_intN_t(b, ~0ull, bit_size), count)); break; default: unreachable("you seriously can't tell this is unreachable?"); } return uint_to_ballot_type(b, val, intrin->dest.ssa.num_components, intrin->dest.ssa.bit_size); } case nir_intrinsic_ballot: { if (intrin->dest.ssa.num_components == 1 && intrin->dest.ssa.bit_size == options->ballot_bit_size) return NULL; nir_intrinsic_instr *ballot = nir_intrinsic_instr_create(b->shader, nir_intrinsic_ballot); ballot->num_components = 1; nir_ssa_dest_init(&ballot->instr, &ballot->dest, 1, options->ballot_bit_size, NULL); nir_src_copy(&ballot->src[0], &intrin->src[0], ballot); nir_builder_instr_insert(b, &ballot->instr); return uint_to_ballot_type(b, &ballot->dest.ssa, intrin->dest.ssa.num_components, intrin->dest.ssa.bit_size); } default: break; } return NULL; } static bool lower_subgroups_impl(nir_function_impl *impl, const nir_lower_subgroups_options *options) { nir_builder b; nir_builder_init(&b, impl); bool progress = false; nir_foreach_block(block, impl) { nir_foreach_instr_safe(instr, block) { if (instr->type != nir_instr_type_intrinsic) continue; nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr); b.cursor = nir_before_instr(instr); nir_ssa_def *lower = lower_subgroups_intrin(&b, intrin, options); if (!lower) continue; nir_ssa_def_rewrite_uses(&intrin->dest.ssa, nir_src_for_ssa(lower)); nir_instr_remove(instr); progress = true; } } return progress; } bool nir_lower_subgroups(nir_shader *shader, const nir_lower_subgroups_options *options) { bool progress = false; nir_foreach_function(function, shader) { if (!function->impl) continue; if (lower_subgroups_impl(function->impl, options)) { progress = true; nir_metadata_preserve(function->impl, nir_metadata_block_index | nir_metadata_dominance); } } return progress; }